FIBER TYPE OPTICAL MODULATOR

摘要

PURPOSE:To facilitate connection with an optical fiber system and to improve the stability, and to also simplify the constitution by allowing light and an ultrasonic wave to operate on each other at the melt-sticking or melt-sticking and drawing part of plural optical fibers. CONSTITUTION:An ultrasonic wave generated by an electrostrictive oscillator 11 propagates and is converged through a Q fiber 12 to propagate to the melt-sticking and drawing part 18 through an incidence-side fiber 13. Light incident on an incidence-side optical fiber 15 in the direction of an arrow Y6 is supplied to a fiber polarizer 17 to excite only (y) polarization and then enters the melt-sticking and drawing part 18. Then when the ultrasonic wave having a wave number K and a frequency fs and the light having a propagation constant betay and an frequency (f) operate on each other at the melt-sticking and drawing part 18 and the sum of the constant betay and wave number K is equal to a propagation constant betax, the (y)-polarized light is converted into an (x)- polarized wave and the frequency shifts from (f) to f+fs at the same time. For the purpose, only tye (x)-polarized light is extracted from the propagating light of a projection-side optical fiber 19 by a fiber polarizer 20 to obtain light having the frequency shift.